Cause-specific or relative survival setting to estimate population-based net survival from cancer? An empirical evaluation using women diagnosed with breast cancer in Geneva between 1981 and 1991 and followed for 20 years after diagnosis.

BACKGROUND: Both cause-specific and relative survival settings can be used to estimate net survival, the survival that would be observed if the only possible underlying cause of death was the disease under study. Both resulting net survival estimators are biased by informative censoring and prone to biases related to the data settings within which each is derived. We took into account informative censoring to derive theoretically unbiased estimators and examine which of the two data settings was the most robust against incorrect assumptions in the data. PATIENTS AND METHODS: We identified 2489 women in the Geneva Cancer Registry, diagnosed with breast cancer between 1981 and 1991, and estimated net survival up to 20-years using both cause-specific and relative survival settings, by tackling the informative censoring with weights. To understand the possible origins of differences between the survival estimates, we performed sensitivity analyses within each setting. We evaluated the impact of misclassification of cause of death and of using inappropriate life tables on survival estimates. RESULTS: Net survival was highest using the cause-specific setting, by 1% at one year and by up to around 11% twenty years after diagnosis. Differences between both sets of net survival estimates were eliminated after recoding between 15% and 20% of the non-specific deaths as breast cancer deaths. By contrast, a dramatic increase in the general population mortality rates was needed to see the survival estimates based on relative survival setting become closer to those derived from cause-specific setting. CONCLUSION: Net survival estimates derived using the cause-specific setting are very sensitive to misclassification of cause of death. Net survival estimates derived using the relative-survival setting were robust to large changes in expected mortality. The relative survival setting is recommended for estimation of long-term net survival among patients with breast cancer

Estimation of net survival for cancer patients: Relative survival setting more robust to some assumption violations than cause-specific setting, a sensitivity analysis on empirical data.

Net survival is the survival that would be observed if the only possible underlying cause of death was the disease under study. It can be estimated with either cause-specific or relative survival data settings, if the informative censoring is properly considered. However, net survival estimators are prone to specific biases related to the data setting itself. We examined which data setting was the most robust against violation of key assumptions (erroneous cause of death and inappropriate life tables). We identified 4285 women in the Geneva Cancer Registry, diagnosed with breast, colorectal, lung cancer and melanoma between 1981 and 1991 and estimated net survival up to 20 years using cause-specific and relative survival settings. We used weights to tackle informative censoring in both settings and performed sensitivity analyses to evaluate the impact of misclassification of cause of death in the cause-specific setting or of using inappropriate life tables on net survival estimates in the relative survival setting. For all the four cancers, net survival was highest when using the cause-specific setting and the absolute difference between the two estimators increased with time since diagnosis. The sensitivity analysis showed that (i) the use of different life tables did not compromise net survival estimation in the relative survival setting, whereas (ii) a small level of misclassification for the cause of death led to a large change in the net survival estimate in the cause-specific setting. The relative survival setting was more robust to the above assumptions violations and is therefore recommended for estimation of net survival

Evaluation épidémiologique du programme genevois de dépistage du cancer du sein, 2012-2017

Malgré une baisse de l’incidence et de la mortalité, le cancer du sein demeure le plus fréquent et le plus mortel chez la femme avec environ 370 femmes touchées chaque année à Genève et 80 qui en décèdent. Le dépistage par mammographie reste le seul moyen dont l’efficacité est scientifiquement prouvée pour diminuer son impact. Le cancer du sein est le plus fréquent et le plus mortel. Des évaluations indépendantes et régulières permettent de s’assurer que la qualité et l’efficacité d’un programme de dépistage répondent à des normes internationales. Le mandat d’évaluation du programme genevois de dépistage du cancer du sein a été confié au Département épidémiologie et systèmes de santé du Centre universitaire de médecine générale et santé publique à Lausanne (Unisanté)a, en charge de l’évaluation de nombreux programmes de dépistage en Suisse et de la précédente évaluation du programme genevois. Evaluation externe du programme par un centre expert. Deuxième évaluation du programme genevois par Unisanté. Ce rapport porte sur la période 2012 à 2017. Il inclut une évaluation de l’activité du programme, de son utilisation, de sa qualité et de son efficacité. En outre, des analyses de l’impact de l’introduction de la lecture de consensus et de l’effet de l’intervalle entre deux dépistages sur la précocité diagnostique sont présentées. Evaluation de l’activité, de la participation, de la qualité et de l’efficacité entre 2012 et 2017. L’activité du programme continue de croître, atteignant en 2018 plus de 13'000 mammographies réalisées. Grâce à l’augmentation du nombre de mammographies et aux mesures prises par le programme (réduction du nombre de radiologues ; complément de lectures avec un logiciel d’entraînement), le volume de lectures par radiologue respecte les normes suisses de qualité depuis 2016. La participation au programme reste en-dessous de la moyenne nationale et des normes préconisées, malgré une tendance à la hausse. Sur 10 femmes invitées, 3 participent et, parmi les participantes, 8 sur 10 répondent positivement à l’invitation suivante (fidélisation). La participation est plus basse chez les femmes dont le résultat du précédent dépistage était un faux-positif. La qualité du programme a vu des améliorations importantes et rapides avec l’introduction de la lecture de consensus en septembre 2014. Depuis ce changement, les taux de reconvocation et de faux-positifs ont fortement baissé et satisfont les normes européennes en tour incident, mais pas en tour prévalent. La qualité radiologique du programme genevois est désormais au moins similaire à la moyenne des programmes suisses, mais demeure inférieure à celle des programmes romands. La fréquence des cancers d’intervalle du programme genevois satisfait la norme européenne de qualité en première mais pas en deuxième année après le dépistage. L’efficacité du programme atteint en grande partie les normes européennes et demeure stable depuis la dernière évaluation. La proportion de cancers de stade avancé reste trop élevée. Un long délai (>26 mois) entre deux dépistages influence marginalement le profil pronostique des cancers dépistés. Ce profil est nettement plus favorable que celui des cancers d’intervalle et des cancers diagnostiqués suite à des symptômes. La précocité diagnostique des cancers dépistés par le programme est largement comparable à celle des cancers dépistés en dehors du programme. Les performances du programme se traduisent, pour 1000 participations, par 946 résultats de mammographie normaux (vrais négatifs), 54 résultats faussement positifs (dont 6 donnent lieu à une investigation invasive), 5 cancers dépistés (1 in situ, 2 de stade précoce et 2 de stade avancé) et 2 cancers d’intervalle, ce qui équivaut à une sensibilité du programme de 79,4% et une spécificité de 93,7%. Chez les femmes de 70 à 74 ans, invitées depuis 2014, la qualité du dépistage est accrue et la participation est comparable à celle des femmes de 50 à 69 ans. Ces résultats donnent lieu à trois recommandations : 1.Poursuivre les efforts de diminution du taux de reconvocation en tour prévalent 2.Organiser des relectures périodiques des clichés 3.Documenter rigoureusement les mesures et stratégies mises en place pour améliorer la qualité du programme

Changing pattern of age-specific breast cancer incidence in the Swiss canton of Geneva

Hormone replacement therapy (HRT) use declined sharply after mid-2002, when the Women's Health Initiative trial reported an association between breast cancer occurrence and HRT. Hypothesized mechanism behind this association is that HRT promotes growth of pre-existing small tumors, leading to earlier tumor detection. We evaluated the impact of the sudden decline in HRT use on age distribution of breast cancer in Geneva. We included all incident breast cancer cases recorded from 1975 to 2006 at the Geneva cancer registry. We calculated mean annual incidence rates per 100,000 for 2year periods for three age groups and assessed temporal changes by joinpoint regression. We compared age-specific incidence curves for different periods, reflecting different prevalence rates of HRT use. After increasing constantly between 1986 and 2002 among women aged 50-69years [annual percent change (APC): +4.4, P<0.0001], rates declined sharply after 2003 (APC: −6.0; P=0.0264). Age-specific breast cancer rates changed dramatically with changes in prevalence of HRT use. During low HRT prevalence, breast cancer incidence increased progressively with age, when HRT prevalence was reaching its maximum (1995-2002), higher rates were seen in 60- to 64-year-old women, with a concomitant decrease in risk among elderly. After the sudden decline in HRT use, the incidence peak diminished significantly and incidence increased again with age. Following the abrupt decline in HRT use in Geneva, breast cancer incidence rates among post-menopausal women decreased considerably with striking changes in age-specific incidence rates before, during and after the peak in HRT prevalenc

Accuracy of cause of death data routinely recorded in a population-based cancer registry: impact on cause-specific survival and validation using the Geneva Cancer Registry.

BACKGROUND: Information on the underlying cause of death of cancer patients is of interest because it can be used to estimate net survival. The population-based Geneva Cancer Registry is unique because registrars are able to review the official cause of death. This study aims to describe the difference between the official and revised cause-of-death variables and the impact on cancer survival estimates. METHODS: The recording process for each cause of death variable is summarised. We describe the differences between the two cause-of-death variables for the 5,065 deceased patients out of the 10,534 women diagnosed with breast cancer between 1970 and 2009. The Kappa statistic and logistic regression are applied to evaluate the degree of concordance. The impact of discordance on cause-specific survival is examined using the Kaplan Meier method. RESULTS: The overall agreement between the two variables was high. However, several subgroups presented a lower concordance, suggesting differences in calendar time and less attention given to older patients and more advanced diseases. Similarly, the impact of discordance on cause-specific survival was small on overall survival but larger for several subgroups. CONCLUSION: Estimation of cancer-specific survival could therefore be prone to bias when using the official cause of death. Breast cancer is not the more lethal cancer and our results can certainly not be generalised to more lethal tumours

High burden of invasive and non-invasive cancer among women aged 20–49 years: the situation in Geneva, Switzerland

Background: The pattern of cancer among young adults aged 20-49 years is different than that observed in other age groups, most notably women present higher rates than those observed among men. Estimations of the burden of cancer disease among women of this age group, however, rarely include both invasive and non-invasive disease. Methods: We calculated incidence rates of invasive and non-invasive cancers for women and men aged 20-49 years and by cancer site for the period 2014-2018 in the canton of Geneva, Switzerland using data from the population-based cancer registry. Results: Between 2014 and 2018, the incidence rates of invasive and non-invasive cancers among women were 177.6/100,000 and 166.4/100,000, respectively. The rates among men of the same age were 110.6/100,000 and 31.8/100,000, respectively. Just three cancers, breast, thyroid and melanoma accounted for 70% of all invasive cancers among women. In situ cervical cancer represented over 70% of non-invasive disease. Conclusion: Cancer among women aged 20-49 years is quite frequent. This is primarily a result of increasing risk, increased diagnosis or both and highlights the need for better primary prevention strategies, personalized risk assessment and tailored screening, as well as increased awareness of women and health professionals about health risks in young adults.</p

Le Cancer à Genève: Incidence, mortalité, survie et prévalence 2007-2010

Tous les quatre ans, le Registre genevois des tumeurs, crée en 1970, publie un rapport sur l'incidence, la mortalité et la survie par cancer dans la population genevoise. Il a pour objectif de recenser l'ensemble des cancers diagnostiqués dans la population résidente du canton

Testicular cancer in Geneva, Switzerland, 1970-2012: incidence trends, survival and risk of second cancer

This paper describes the testicular cancer trends for incidence, survival, socio-economic status (SES) disparities and second cancer occurrence in Geneva, Switzerland, a high-risk population